Timing belts are used in various metering, positioning, conveying, and oscillating drives for instruments, mechanisms, tools, etc. Timing belts are formed of durable plastics, such as neoprene and polyurethane, which may be reinforced by tensile metal cords. Timing belts vary in width, the number of protrusions, the type of the plastic suitable for the operating conditions imposed upon the timing belt, and other parameters.
Timing belts are available in commonly used, or standard, lengths. Where belt lengths are required that are longer than the standard lengths stocked by suppliers and distributors of precision mechanical components, a new, longer belt is formed from a length of timing belt stock. A clamp is used to join the opposing ends of the length of belt stock into an endless belt. The resulting endless belt is greater in length than the standard belts, and is capable of addressing the specific requirements of the user.
Diverse clamps have been devised for securing together the opposing, free ends of a length of timing belt, drive belt, etc., to form a continuous loop. For example, U.S. Pat. No. 5,338,265, discloses an emergency drive belt apparatus including a first connector assembly 17 attached to the first end 14 of the belt 12, and a second connector assembly 23 attached to the second end of the belt 12. Triangular shaped teeth 19, 25, of complementary shape, on the opposing ends of the belt, are forced together by a locking member 18 that assumes the form of a flexible sleeve.
Another clamp, available for purchase from the Stock Drive Division of Designatronics, Inc., of New Hyde Park, N.Y., the assignee of the present invention, comprises a flat, rectangular top plate, a rectangular grooved clamp plate, or base, with aligned apertures extending through the top plate and clamp plate. The upper surface of the clamp plate has parallel grooves formed therein. The grooves are shaped and sized to receive the complementary teeth formed on one side of a length of belt stock. An aperture is formed inwardly of each corner of the top plate and the clamp plate. Fasteners, such as bolts with threaded shanks, are inserted through the apertures and are received in nuts on the underside of the clamp plate. The nuts and bolts are tightened to draw the top plate and clamp plate together, sandwiching the free ends of the belt stock therebetween. The ends of the belt stock are retained inwardly of the bolts, thus limiting the range of belt widths to which the clamp may be applied.
The several fasteners used to join the foregoing clamp together render the clamp difficult to install and/or replace, particularly in tight spaces. Also, the clamp is relatively expensive, since it requires several machining operations to produce same. Furthermore, known clamps are relatively bulky and heavy, and impose stresses on the timing belt which limit the speed of the belt.
Consequently, the need for a simple, low cost, inexpensive, easily installed belt clamp, relying upon a single fastener to join the components of the clamp securely together, remains undiminished. Also, the requirement for such a belt clamp, that can function effectively with single sided, or dual sided, lengths of timing belt stock, remains unfulfilled. Furthermore, the requirement for a lightweight, sturdy belt clamp of reduced width, that will accommodate belts of different widths and different configurations of protrusions, such as ribs, teeth, or buttons, remains unsatisfied. Lastly, the need for a belt clamp, that functions as a platform for mounting a position indicating device, such as a pointer, magnet, optical sensor, or other position locating device, remains unmet.